Sun Valley weather in December
December in Sun Valley: freezing, a little rain, with clean air — a great time to visit.
#6 of 12 months in Sun Valley · #195 of 604 destinations to visit in December · comfort 78/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
Sun Valley climate normals — December
| Daytime high | -1°C / 31°F | 🥶 freezing |
|---|---|---|
| Nighttime low | -11°C / 13°F | |
| Feels like (high) | -4°C / 25°F | |
| Rainfall | 58 mm / 2.3 in | 🌦 some rain |
| Rainy days | 10 days | |
| Humidity | 80% | 💦 very humid |
| Dew point | -9°C / 15°F | |
| Sunshine | 6.3 h/day | |
| Daylight | 9 h | |
| Wind | 9 km/h / 5 mph | |
| Snowfall | 59.1 cm / 23.3 in | |
| Air quality (US AQI) | 40 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Sun Valley in December — FAQ
- Is December a good time to visit Sun Valley?
- December in Sun Valley: freezing, a little rain, with clean air — a great time to visit. It ranks #6 of 12 months for Sun Valley on SeasonMap's comfort score (78/100).
- What is the weather like in Sun Valley in December?
- In December, Sun Valley averages a daily high of -0.7°C and a low of -10.7°C, with about 57.6 mm of rain over roughly 10.4 rainy days.
- What is the air quality in Sun Valley in December?
- Sun Valley has a mean US Air Quality Index of about 40 in December.
- Does it snow in Sun Valley in December?
- Sun Valley sees roughly 59.1 cm of snowfall in December.